Electrodeposition of metals



H. A. SEDGWI.CK ET AL (.ELECTRODEPO'SITICN OF METALS Filed June 27, 1921' 2 Sheets-Sheet 2 July 7, 1925.

Patented July 7, 1925.

UNITED STATES PATENT OFFICE.

HARRY A. SEDGWICK AND PATRICK J. SHEEHAN, OE MILWAUKEE, WISCONSIN.

ELEomonErosrTIoN 0F METALS.

Application filed June 27, 1921.

To all whom it may concern:

Be it known that we,'HARRY A. Snnowrc: and PATRICK J. SHEEHAN, citizens of the United States, residing at Milwaukee, in the-county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Electrodeposition of Metals, of which the following is a full, clear, concise, and e-Xactdescription, reference being had to theaccompanying drawing, forming a part of this specification.

This invention relates to electro-deposition of metals.

In our Patent No. 1,367,567, issued February 8, 1921, are disclosed certain improvements in electro-plating apparatus, which improvements have proven of great value industrially and commercially, and the present invention has among its objects that ofproviding an improved method of electrodeposition involving certain features of said prior patent.

Another object is that of providing such a method enabling curtailment of the time, current and mechanical power required to act upon a given quantity of material and whereof the finished output is materially im roved.

other object is that of providing such a method enabling material reduction in the quantity of electrolyte required.

Another object is that of providing such a method involving a minimum of leakage loss of the plating current. I 1

Another object is that of providing apparatus for performance of the foregoing method.

Another object is that of providing such apparatusv adapted to effect uninterrupted electro-deposition and whereof the space requirements corresponding with a given rate of output are very considerably reduced.

Other objects and advantages will hereinafter appear.

According to the present method, the heat liberated during the electrolytic action is conserved and utilized for raising the temperature of the electrolyte, the quantity of the latter beingreduced as far as permissible as hereinafter set forth, whereby the liberated heat is suflicient to bring the electrolyte temperature approximately to the boiling point of water at which temperature the plating action is very materially facilitated and expedited.

Thus in practice the electrolyte, having 7 Serial No. 480,785.-

the material to be treated immersed therein, is entirely enclosed and is heat insulated from the surrounding air and from other heat absorbing agencies, the space between electrodes of opposite polarity being re- Fig. 3 is a detail plan view of certain fea-' tures of Fig. 2 as Viewed from beneath.

In a preferred form of the present apparatus the material undergoing treatment is charged within one or more liquid tight containers, each having therein a quantity of. electrolyte and also containing metal to be deposited, the container being composed of wood or other electrical and heat insulating material and having electrical connections with a suitable source of direct current such as to'render the material undergoing treatment negative and the aforementioned body of metal to be deposited positivewith respect to such current source, the container being revolved or rotated to effect agitation of the material for insuring even deposition of the coating of metal thereon.

Referring to the drawing, the same illustrates a plurality of containers 5 'of the character aforedescribed mounted upon and secured to a rotatable frame comprising substantially similar, end members. axially secured in spaced relation upon a rotatable shaft 6, the latter being in turn carried but'insulated from one another, said cylindrical sections 10 being mounted directly upon the shaft 6.

In practice one, or optionally both, ofthe aforementioned sections 10 is furnished with gear teeth providing for driving of the aforedescribed frame and containers by means'of an electric motor 12 acting through suitable reduction gearing indicated at 18.

Slip rings 14 and 15 are carried by the the respeetive .sections spaced and insulated relation to the latter: Brushes 17 and 18 are adapted to co-operatg with the respective slip rings for connecting the latter with a source of direct current, not shown.

Each of the web sections 11 is further pro vided upon. its internally arranged face with a number of pairs of substantially radial flanges 19 equal to the number of containers provided, said flanges being located adjacent the peripheries of said web sections and the flanges of each section being arranged parallel with the corresponding flanges-of the other. Each of the respective containers 5 is also provided with end plates having correspondingly spaced and directed flanges 20 adapted to co-operate with the flanges of the aforedescribed sections for support and securement of the containers by and between said web sections of the frame and in electrical connection therewith and also providing for removal 'or replacement of the individual containers by radial movement of the latter. The con tainers are normally held against outward movement with reference to the frame by means of hooks 21 having their reflexed ends engaged within suitable openings of the respective web members and having-their opposite terminal portions extending through suitably disposed openings in the corresponding end plates of the container, said terminal portions being screw-threaded to receive nuts or other releasable clamping and securing means.

Each of the aforementioned containers comprises a sitbstantial fluid tight cylindrical structure barrel having a peripheral portion 22 and end portions In practice a section 24 of the peripheral portion 22 is formed distinct and separable from the remaining portion, thus affording access to the interior of the: container, whereas clamping and securing means such as those illustrated are employed for releasably securing such removable section in place during operation of the device.

An anode 25'comprising metal to be de posited is carried within and preferably centrally of each receptacle. Such anode may be of any desired or preferred form but for convenience has been illustrated as substantially cylindrical and is preferably secured by means of rigid bolts or studs 26 and 27. screwed inwardly through the cor-- responding end plates of the container and into the adjacent terminal portions of the anode said studs being preferably secured in place by means of suitable nuts 28. The stud 26 of each receptacle is in electrical contact with the adjacent end plate of such a receptacle, whereas the studs 27 are insulated from their associated end plates, the latter being cut away to space the same from said studs as shown. The end portions of each container are provided centrally with openings through which the respective studs 26 and 27 extend, said openings being normally closed'by the adjacent end plates and one of the openings being-of suflicient size to permit insertion or removal of] the anode therethrough. y

Thus assuming construction of'the con tainer of insulatingmaterial the aforedescribed arrangement providesfor electrical connection of the anode to the oneweb sec tion of theframe but insulated from the other web section when the container is mounted in operative relation.

A plurality of strips or bars29 of conductive'material such as copper are secured.

within and preferably closely adjacent to the interior surface of'the several containcharging of the containers with material to be treated, said containers being mounted and secured as shown, the current traversing the device is adapted to carry away metal from the anodes and to deposit the same upon such material undergoing treatment,

the conductive strips 29' being so located and arranged as to insure electrical contact of such material with at least one of such conductive strips at all times, whereas-due to the continuous rotation of the support car.- rying the receptacles the latter are caused to revolve continuously with consequent shifting of the material undergoing treatment whereby even and uniform deposition of metal thereon is promoted. Since the aforedescribed action of the device ordinarily involves liberationof considerable quantities of gas or vapor or both. the means now to be described are employed for permitting escape of. such products from the interior of the containers without, however, permitting escape of the contained electrolyte or of the material undergoing treatment.

' For such purpose each container is provided with a normally closed valve 32 adapted to open inwardly whereby any increase in fluid pressure within the receptacle tends to maintain the valve seated and to resist. unwarranted opening thereof. Said valves are preferably so located with reference to their respective containers as to bring all. of said valves within the arc of a relatively small circle surrounding the shaft 6. Each valve is preferably provided with a hollow stem 33 extending outwardly through the wall of the container and terminating in a beveled or rounded head 34, said stem having suitable openings 35 to be uncovered upon inward movement of the valve. A spring 36 is compressed between said head and a portion of the container for resiliently holding the valve closed. Axially shiftable tappets 37 are carried by the adjacent web section 11 in register with the respective heads 34 of the several valve stems, said tappets being'preferably provided with, en-

larged heads for direct cooperation with said valve heads while springs 38 serve tohold said tappet heads outwardly with reference to the respective containers A cam member 39 is carried'by the framej9 in a relation to engage the tappets 37 successively and singly for forcing the latter toward their respectively associated valves each at a stage of revolution of itscontainer such that the, alve is located above the surface of the contained electrolyte, as shown particularly in Fig. 2.

Thus, at each revolution of the device the valve of each container is opened for permitting escape of the liberated gas or vapor, the aforementioned springs serving to effect. closure of the valve as soon as the tappet passes the cam 39, said springs further acting in conjunction with fluid pressure to prevent unwarranted opening of the valve.

' In the operation of the complete device the containers are charged successively with electrolyte and material to be treated and are secured upon the frame. As soon as one or more of the containers is so charged and mounted, current is passed continuously through the circuit of the slip rings. When all or the desired number of containers are so charged, the motor 12 is started for effecting rotation of the device. After operation of the device for the necessary period,

said motor is stopped and a container, preferably the one first charged, is removed, dumped and recharged, a freshly charged container being preferably substituted for the one removed. Such operation may be effected in a few minutes or even in a few seconds under favorable conditions and does not necessitate cutting off the plating cur rent from the other containers.

By this means the device is adapted to operate continuously whereby its output is greatly increased over that of devices which require interruption of the plating current during recharging.

Further the device involves no stationary electrolyte tank as'distinguished from the containers which hold the material undergoing treatment, each of said containers rotation of theframe being correspondingly reduced.

The aforedescribed apparatus is thus well adapted to performance of the present method since the use of the closed contain-J ers, composed preferably of wood, serve to prevent loss of the electrolytically liberated heat and to insure utilization of such heat for raising the temperature of the electrolyte, the required quantity of the latter being much reduced, as described, whereby the resultant temperature rise thereof is further very materially increased.

Thus, under suitable conditions the tem perature rises automatically and. very rapidly approximately to the boiling point of water, under which conditions the electro lytic action is greatly expedited and facilitated and the character of the finished product improved particularlyas regards uniform deposition of material over surfaces having depressions therein.

What we claim as new and desire to secure by Letters Patent is:

1. In a method of electro-deposition of metals, the step which comprises reduction of the electrical resistance of the electro-' lyte by conserving therein practically the total quantity of heat generated as a re-- sult of passage of an electric currenttherethrough.

2. The method of electro-deposition of metals, which comprises subjecting the electrolyte to inherent conditions of temperature and pressure, and regulating the effect of certain of said conditions. I

3. The method of electro-deposition of metals which comprises conservation and utilization of electrolytically liberated heat energy for raising the temperature of the electrolyte under conditions of pressure control to thereoy facilitate and expedite the electrloytic action.

LThe method of electro-deposition of metals vwhich comprises conservation and utilization of substantially all the electrolytically liberated heat energy for raising the temperature of the electrolyte while controlling the pressure thereupon to thereby facilitate and expedite the electrolytic action. I

5. The method of electro-deposition of metals which comprises utilization of electrolytically liberated heat energy for varying the temperature of the electrolyte approximately tothat at which water boils while regulating the pressure thereupon, to

gation and heat insulation of the electro- 25 lyte to thereby conserve the electrolytically liberatedheat energy and utilization of the heat energy so conserved for raising the temperature of the electrolyte while regulating the pressure thereupon to facilitate the electrolytic action.

8. Apparatus for electro-deposition of metals, comprising a closed container to re ceive an electrolyte and material to be electroplated, electrodes in said container, and means for controlling the pressure of gas evolved in said container during the electro plating operation.

9. Apparatus for clectro-deposition of metals, comprising a support, a rotatable shaft carried by said support, a plurality of substantially fluid tight containers arranged around and carried by said shaft, electrodes in each of said containers for connection with a suitable source of current, means for admitting an electrolyte and material to be treated into each of said containers, a valve on each of said containers for controlling the pressure therein, and means for rotating said shaft and conainers.

10. Apparatus for electro-deposition of metals, comprising a support for a rotatable shaft, a plurality of fluid tight,containers carried by said shaft, means for admitting an electrolyte and material to be treated into each container, a body of' metal tobe electrically transferred arranged, in each container and forming an electrode in contact with the electrolyte, another electrode arranged in each container in contact with said material, means for connecting said electrodes-to a source of current, valves on said containers, and cooperating means on said support to actuate said valves when said shaft and containers are rotated to thereby regulate the pressure within said containers.

11. Apparatus for 'electro-deposition of metals, comprising a substantially fluid tight container to hold an electrolyte and loose solid material to be metal coated, a body comprising metal to be deposited carried within said container and in contact with said electrolyte, means for connecting said material and said anode with a suitable source of current, means for revolving said I container to efiect relative movement of the contents thereof and means forv regulating the fluid pre'ssure in. said container? .12. Apparatus for e lectro-deposition of metals, comprising a substantially fluid tight container to hold an electrolyte and loose solid material to be'treated, a body comprising metal to be electrically transferred car ried within said container and in contact with said electrolyte, means for connecting said body and said material with a suitable source of current, means for moving said container to efiect relative movement of the contents thereof and means permitting escape of gas from said container.

13. Apparatus for electro-deposition of metals, comprising a substantially fiuid tight container to hold an electrolyte and immersed 'materialto be treated, a body comprising metal to be electrically transferred carried within said container and in-contact with said electrolyte, means for connecting said body and said material with a suitable source of current, means for rotating said container to effect agitation of the contents tliereof, and means for periodically establishingand interrupting communication between the interior of said container and atmosphere to thereby permit escape of electrolytically liberated gas while preventing loss ofliquid electrolyte.

14. The combination with a support, of a rotatable shaft carried thereby, electrically insulated frame members rigidly mounted upon said shaft, an electrolyte container to be carried by and between said frame members, saidcontainer having interiorly located electrodes in contact with the contained electrolyte but otherwise insulated from one another, said frame members and said container having co-operating flanges providing for support and securement of the latter upon the former and also providing electrical connections for said electrodes.

15. Apparatus for electro-deposition of metals, comprising a support, a rotatable shaft carried thereby, spaced end members axially connected to said shaft, a plprality of pairs of substantially radial 'flaI rgs on the adjacent faces of said end'ane nbers, a plurality of substantially liquid tight containers having means for engagement with parts in engaging relation.v

' member for connecting one electrode in each container with a source of current, means associated with another web member for connecting another electrode in' each container with a source of current, and means permitting removal of one or more of said containers from said web members without interrupting-the'flow of current to other of said containers.

17 Electroplating apparatus comprising a rotatable support for a plurality of electroplating tanks, and means permitting removal of certain of said tanks from said support during the electroplating operation without interrupting the electroplating operation of other of said tanks.

18. Electroplating apparatus comprising a horizontally rotatable support for a p1u- 'rality of radially arranged electroplating tanks, a pair of electrodes in contact with an electrolyte in each tank, means connecting said electrodes with a source of current, and means for discontinuing the electroplating operation in.'one or more of said tanks without interrupting the electroplating operation in other of said tanks.

In witness whereof, We have hereunto subscribed our names.

HARRY A. SEDGWICK. PATRICK I J. SHEEHAN. 

